Perfusate preparation for ophthalmic operation

ABSTRACT

A one-pack preparation of irrigating solution for ocular surgery of cataract, glaucoma or intraocular lens transplantation, which is excellent in the protection of ophthalmic tissues and endothelial cells during and after the operation and has a high in vivo stability. The preparation comprises an aqueous solution containing at least one compound selected from D-3-hydroxybutyric acid and water-soluble salts thereof, at least one compound selected from water-soluble bicarbonates, phosphoric acid and water-soluble phosphates, a water-soluble calcium salt, and a water-soluble magnesium salt.

This application is a 371 of PCT/JP98/04757 filed on Oct. 21, 1998.

1. Technical Field

The present invention relates to a preparation of irrigating solutionfor ocular surgery which may be used in the surgery of cataract,intraocular lens transplantation or glaucoma. More specifically, itrelates to a preparation of irrigating solution which is suitable forprotecting intraocular tissues, removing the substances left in the eyeafter the surgery by suction and preventing the surface of the cornealepithelium and the conjunctiva from drying in order to perform thesurgery safely and effectively.

2. Background Art

Recently, development of ocular surgery methods for surgery of cataract,intraocular lens transplantation, glaucoma and the like has remarkablyprogressed. An irrigating solution which is used as a surgical adjuvantplays an important role in order to perform the above surgery safely andeffectively. For example, when the periphery of the cornea is incised bya scalpel at the start of the surgery of cataract, the aqueous humorflows out from the anterior chamber immediately. Therefore, injection ofan irrigating solution and a viscoelastic substance is indispensable forprotecting intraocular tissues and cells and for maintaining the spaceof the anterior chamber. Further, when the irrigating solution ispresent in the eye at the time of breaking the opaque crystalline lensinto pieces and extracting them, the pieces can be removed smoothly bysuction. The irrigating solution is also used for preventing thesurfaces of the cornea and the conjunctiva from drying during operation.

Some important points in the preparation for achieving such applicationpurposes of the irrigating solution are as follows: (1) the osmoticpressure and pH of the preparation must be physiologically harmonizedwith the intraocular tissues and the corneal endothelial cell; 2) theessential compounds of aqueous humor components such as inorganic salts,energy sources and cell-activators must be added; 3) the preparationmust be biologically safe; and 4) the preparation must be able to bepreserved at room temperature for the long term.

One of preparation of irrigating solution for ocular surgery which arecurrently available in Japan's market is a commercial product containingoxyglutathione as a cell-activator, and another commercial producthaving a bicarbonate ion-based buffer system has already beenpractically used. However, since these are a two-pack preparation whichrequires two types of solutions to be mixed prior to use or apreparation which contains no ingredients effective for protecting thecorneal endothelial cell, they have not a few problems to be solved withregard to stability, simplicity at the time of use and efficacy as apreparation.

A preparation of irrigating solution for ocular surgery which iscomposed essentially of 3-hydroxybutyric acid as an energy source isdisclosed in the specifications of U.S. Pat. Nos. 5,116,868 and5,298,487. However, the preparations described in the specifications donot contain bicarbonate ions necessary to sustain the function of thecorneal endothelial cell. The disclosed reasons why the preparation doesnot have to contain the bicarbonate ions in advance are that when thebicarbonate ions exist in the preparation, the pH of the preparationfluctuates due to a CO₂ partial pressure, whereby the preparationbecomes unstable, and that 3-hydroxybutyric acid generates CO₂ throughmetabolism and the CO₂ changes into the bicarbonate ions which aretherefore supplied automatically. In addition, sodium acetate, which isgenerally said to be absent in human aqueous humor, is contained in theabove preparation.

D-3-hydroxybutyric acid or its salts used as active ingredients in thepresent invention are known to be biological substances existing inhumans and most of other mammals, biosynthesized through an oxidationprocess of fatty acids in the liver, and carried into the cornea as wellas peripheral tissues out of the liver by blood to be utilized as anefficient energy source (refer to Lehninger, New Biochem., 2nd Ed.,p625, 1993 and NATURE, No.4, 841, p597, 1962). It is also known that thesubstances are much more useful for corneal tissues as an energy sourcethan glucose (refer to TRANSPLANTATION, 57, p1778-1785, 1994).

D-3-hydroxybutyric acid or its salts are oxidized in the TCA cycle ofthese tissues to produce ATP and are eventually converted into carbondioxide and water (refer to NATURE, No.4841, p597, 1962).

As for the application of D-3-hydroxybutyric acid and its salts todrugs, it has been reported that they are mixed into an infusionsolution for supplying nutrients to patients in the accelerated state asto biological protein catabolism or those having an invaded body (referto Japanese Patent Application Laid-Open No. 191212/1990).

It is disclosed in GANKA RINSHO IHO, Vol.92, No.7 (1998), p902-905, thatthe influence of an intraocular irrigating solution containingβ-hydroxybutyrate on the retinas has been studied on anelectroretinogram (ERG) using the retinas extracted from rabbits andthat the intraocular irrigating solution sustains retinal functionswhich are equal to or more than the market product BSS PLUS (registeredtrademark) does. However, the D-form of β-hydroxybutyrate is notdisclosed in this report, and only the influence of β-hydroxybutyrate onthe retinas is disclosed.

In addition, the Proceeding 201 of the 36th Meeting of the RetinaVitreous Society of Japan held on Jul. 24-26, 1997, discloses that theinfluence of a newly formulated intraocular irrigating solutioncontaining sodium D-β-hydroxybutyrate on the retinas was studied on anERG using the retinas extracted from rabbits and that the newlyformulated intraocular irrigating solution could sustain the ERG of aretinal in vitro sample which is equal to or more than BSS PLUS does.

However, the detailed composition of the above irrigating solution isnot disclosed in this report, and only its influence on the retinas isdisclosed.

DISCLOSURE OF THE INVENTION

It is an object of the present invention to provide a one-packpreparation of irrigating solution for ocular surgery of cataract,glaucoma or intraocular lens transplantation, which is excellent in theprotection of ophthalmic tissues and endothelial cells during and afterthe operation and has a high in vivo stability.

It is another object of the present invention is to provide anintraocular preparation of irrigating solution having formulationstability in addition to the above excellent properties by addinginorganic ions, energy sources, isotonic agents, buffers, bicarbonateions and stabilizers.

Other objects and advantages of the present invention will becomeapparent from the following description.

According to the present invention, the above objects and advantages canbe attained by a one solution-pack preparation of irrigating solutionfor ocular surgery of cataract, glaucoma or intraocular lenstransplantation, which comprises an aqueous solution containing:

(1) at least 0.1 mM but less than 500 mM of at least one compoundselected from the group consisting of D-3-hydroxybutyric acid andwater-soluble salts thereof as a D-3-hydroxybutyrate anion;

(2) at least 0.1 mM but less than 100 mM of water-soluble bicarbonatesalts as a bicarbonate ion;

(3) at least 0.1 mM but less than 50 mM of at least one compoundselected from the group consisting of phosphoric acid and water-solublephosphate salts thereof as a phosphate ion;

(4) at least 0.01 mM but less than 50 mM of water-soluble calcium saltsas a calcium ion; and

(5) at least 0.01 mM but less than 50 mM of water-soluble magnesiumsalts as a magnesium ion.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows the comparison of the cell-activating effects by opticalisomers of 3-hydroxybutyric acid (3-HBA).

FIG. 2 shows the protection effects (in vitro experiments) of thesolution of the present invention and comparative solutions on thecorneas.

FIG. 3 shows the amount of change in the corneal thickness with time byeach of the above solutions.

FIG. 4 shows the recovery effects of D-3-HBA and oxyglutathione on ancultured bovine corneal endothelial cell which is damaged.

FIG. 5 shows the amount of change in the corneal thickness with time bya bicarbonate salts-containing preparation with or without D-3-HBA.

FIG. 6 shows the amount of change in the corneal thickness with time bya bicarbonate salts-free preparation with or without D-3-HBA.

PREFERRED EMBODIMENT OF THE INVENTION

The preparation of the present invention will be described in detailhereinafter.

As for the absolute configuration at the C₃ position in the chemicalstructural formula of 3-hydroxybutyric acid, there is a group of aD-form, a D,L-form and an L-form. Of these, in the present invention,the D-form is used to maximize the effectiveness of a formulation ofirrigating solution for ocular surgery. This is because when thedifference in activity based on the optical isomers with regard to aneffect of activating the corneal endothelial cell, which is one ofmethods for evaluating the effectiveness of the preparation, is studied,activity is obtained with the D-form while it is hardly obtained withthe L-form and because it is thought that when the D,L-form is used, theL-form may cause an adverse effect on the activity.

Since D-3-hydroxybutyric acid and its salts can be synthesized with easeand at high asymmetric yields by asymmetrically hydrogenating the ketonegroups of an acetoacetic ester in the presence of a ruthenium-opticallyactive phosphine complex as a catalyst and subjecting the ester toalkaline hydrolysis, the compounds can be obtained at relatively lowcost (refer to Japanese Patent Publication No.99367/1990).

Preferable examples of the water-soluble salts of D-3-hydroxybutyricacid in the present invention include sodium salts, potassium salts,barium salts, magnesium salts, lithium salts, L-lysine salts,L-histidine salts and L-arginine salts. D-3-hydroxybutyric acid and itswater-soluble salts can be used solely or in combination of two or more.

The term “water-soluble” as used in the present invention refers to theproperty of the compounds which enables the compounds to dissolve in thepreparation of the present invention at the desired concentrationrequired for the preparation.

According to the present invention, the concentration ofD-3-hydroxybutyric acid and/or its water-soluble salts in the aqueoussolution preparation is at least 0.1 mM but less than 500 mM, preferablyat least 1 mM but less than 200 mM, and more preferably at least 5 mMbut less than 100 mM.

In the present invention, the addition of bicarbonate ions exerts aremarkable influence on a cornea-swelling-inhibiting effect, which isone of important indexes for sustaining corneal functions. Actually,when the corneoscleral pieces extracted from rabbits were incubated byusing a preparation containing bicarbonate ions and a preparationcontaining no bicarbonate ions, respectively, and changes in the cornealthicknesses were measured, the preparation containing such ions (thepresent invention) restored the cornea to a nearly normal condition,whereas the preparation containing no such ions accelerated the cornealswelling, proving that it was lacking in the effect of protecting thecornea. Further, the above was also true in an in vivo experiment usingthe eyes of rabbits; that is, the preparation containing such ions (thepresent invention) restored the cornea to a normal condition, whereasthe preparation containing no such ions accelerated the cornealswelling.

In consideration of the above facts, bicarbonate ions must be containedin the D-3-hydroxylutyric acid-containing preparation of the presentinvention.

Preferred examples of the water-soluble bicarbonate salts include sodiumbicarbonate and potassium bicarbonate.

The concentration of the water-soluble bicarbonate salts is at least 0.1mM but less than 100 mM, preferably at least 1 mM but less than 60 mM,and more preferably at least 10 mM but less than 60 mM, as water-solublebicarbonate ions (HCO₃ ⁻).

The preparation of the present invention contains phosphate ions, whichare derived from phosphoric acid or water-soluble phosphate salts. Thephosphate ions are preferably derived from a phosphate-based bufferwhich comprises water-soluble phosphate salts such as disodium hydrogenphosphate, sodium dihydrogen phosphate, dipotassium hydrogen phosphateand potassium dihydrogen phosphate. The phosphate-based buffer ispresent as a component of the human aqueous humor. The concentration ofthe phosphate ions is at least 0.1 mM but less than 50 mM, preferably atleast 0.5 mM but less than 30 mM, and more preferably at least 1 mM butless than 10 mM.

The preparation of the present invention further contains calcium salts.The calcium salts may be added to the preparation of the presentinvention as salts comprising the D-3-hydroxybutyrate ions, bicarbonateions or phosphate ions as described above and calcium ions or as otherwater-soluble salts. Preferable examples of such other water-solublesalts include calcium chloride and calcium glucuronate. The calciumsalts can be used solely or in combination of two or more.

The concentration of the water-soluble calcium salts is at least 0.01 mMbut less than 50 mM, preferably at least 0.1 mM but less than 20 mM,more preferably at least 0.5 mM but less than 10 mM, as calcium ions.

The preparation of the present invention further contains water-solublemagnesium salts. The magnesium salts may be added to the preparation ofthe present invention as salts comprising the D-3-hydroxybutyrate ions,bicarbonate ions or phosphate ions as described above and magnesium ionsor as other water-soluble salts. Preferable examples of such otherwater-soluble salts include magnesium chloride and magnesium sulfate.

The concentration of the water-soluble magnesium salts is at least 0.01mM but less than 50 mM, preferably at least 0.1 mM but less than 20 mM,and more preferably at least 0.5 mM but less than 10 mM, as magnesiumions.

As for the additives to the preparation of irrigating solution in thepresent invention, inorganic salts present in human aqueous humor,glucose as other energy source, isotonic agents and buffers forharmonizing the osmotic pressure and the pH with the intraocular tissuesand the endothelial cells, and stabilizers for preparations and the likeare preferably used as appropriate.

As the inorganic salts and isotonic agents used in the presentinvention, inorganic salts such as alkaline metal salts, e.g., sodiumchloride and potassium chloride, and isotonic agents such ascarbohydrates, e.g., mannitol, sorbitol, xylitol and dextran, arepreferably used in addition to the above calcium salts and magnesiumsalts.

Those can be used solely or in combination of two or more. Theconcentration of the inorganic salts and that of the isotonic agents arepreferably in the range of 0.1 to 1,000 mM. In addition, the osmoticpressure of the preparation is sustained preferably within the range of270 to 350 mOsm.

As the buffers, citric acid, citrate salts, bicarbonate salts, acetatesalts and boric acid-based buffers such as boric acid and sodium boratecan be used in addition to the above water-soluble phosphate salts. Theconcentration of the buffers is preferably in the range of 0.1 to 50 mM.

The pH of the aqueous solution preparation of the present invention ispreferably in the range of 6.8 to 8.2, within which no damages arecaused on intraocular tissues and cells and which is required to sustainthose functions. Further, a pH of 7.2 to 8.0 is more preferably becausethe range has been found to be permissible as an irrigating solution forocular surgery as the result of the functionality and safety tests usingthe eyes of rabbits.

In the present invention, although the main energy source for thepreparation of irrigating solution is D-3-hydroxybutyic acid, glucosemay also be added as an auxiliary sub-energy source. The concentrationof glucose is preferably in the range of 0.1 to 50 mM.

As the stabilizer, water-soluble citrate salts are preferably used.Preferable examples of the water-soluble citrate salts include citricacid, and its sodium salts and potassium salts. Its concentration ispreferably in the range of 0.01 to 50 mM, and more preferably in therange of 0.1 to 10 mM, as citrate ions.

The required amounts of such main components and additives are dissolvedin distilled water in turn, the pHs of the solutions are adjusted bydiluted hydrochloric acid or a diluted alkaline solution, and theresulting solutions can be each preserved in a transparent glass orplastic bottle fitted with a stopper as one-pack preparations. Thethus-prepared preparations were preserved at 40° C. and a humidity of75% for 6 months, and the sample after the 6-month preservation was. thesame as the sample at the start of the test in terms of appearance andosmotic pressure. As for pH, on the other hand, when the concentrationof citric acid or its salts is set to be in the rage of preferably 0.01to 50 mM, more preferably 0.1 to 10 mM, the pH of the preparation at thestart of the test, which is 7.3 to 7.4, is in the range of 7.4 to 7.8 atthe end of the above preservation, indicating that a change in the pH ofthe solution is small and that a stable irrigating solution can beobtained even when bicarbonate ions are present.

EXAMPLES

The following examples are given to further illustrate the presentinvention. However, it should be understood that the present inventionis not limited by these examples.

Example 1

Irrigating solution No.1 (Example) and No.2 (Comparative Example) fortesting were prepared by dissolving the predetermined amounts of thecomponents listed in Table 1 in turn in the order they were listed and,finally, sodium D-3-hydroxy butyrate (to be referred to as “D-3-HBA”hereinafter) in distilled water so as to adjust the total amounts of thesolutions to be 1 liter; adjusting the pHs of the solutions by dilutedhydrochloric acid, and subjecting the solutions to aseptic filtration.The components of Commercial Products B (Comparative Solution 1) and M(Comparative Solution 2) used as additional Comparative Examples and theconcentrations of the components are shown in Table 1.

TABLE 1 (mM) Solution Solution Comparative Comparative Component No.1No.2 Solution 1 Solution 2 NaCl 100.3 100.0 122.2 112.9 KCl 5.1 — 5.084.8 MgCl₂ 1.0 1.0 0.98 — CaCl₂ 1.1 2.0 1.05 1.2 K₂HPO₄ — 5.0 — — Na₂HPO₄3.0 5.0 3.0 — sodium citrate 0.34 10.0 — 3.4 NaHCO₃ 25.0 — 25.0 25.0sodium acetate — 20.0 — 4.4 D-3-HBA 20.0 — — — D,L-3-HBA — 10.0 — —oxyglutathione — — 0.30 — glucose 5.0 5.5 5.11 8.3

Example 2

The preparation stability test of the D-3-HBA-containing solution No.1of Example 1 was performed. Five bottles of the solution to be testedwere prepared by charging 500 mL of the preparation into 600-mltransparent glass containers and capping the bottles. Those werepreserved for 6 months in an instrument maintained at 40±0.5° C. and75±5% humidity. As a result, no changes occurred in the appearances ofthe solutions, the insoluble umpurity test and the osmotic pressure. Asfor the pHs of the solutions, while they were 7.3 to 7.4 at the start ofthe preservation, they became 7.4 to 7.8 after the 6-month preservation,showing relatively small changes. Accordingly, it was found that thepreparation could be preserved stably at room temperature for the longterm.

Example 3

To confirm that the D-form isomer of 3-HBA was the most effective amongthe D-form, D,L-form and L-form isomers thereof, the cell-activatingeffect of each isomer was measured quantitatively by using an incubatedbovine corneal endothelial cell according to the following MTTassay-based method (Chem. Pharm. Bull., 41, 1118, 1993).

The D-form, D,L-form and L-form of D-3-HBA were dissolved in theDULBECCO's MEM salt incubation media at concentrations of 0 (control), 5and 20 mM, respectively, and the resulting solutions were injected intoa 24-well collagen-coated plate implanted (4×10⁴ cell/ml) with apre-incubated bovine corneal endothelial cell and then incubated for 48hrs. After the incubation, 50 μl of cell-counting kit (product of DOJINKAGAKU Ltd.) was added to each well to develop colors, and absorbance at450 nm was measured by using each supernatant. The results are shown inFIG. 1.

As for the cell-activating effects of the D-form, D,L-form and L-f form,the cells incubated in the presence of D-3-HBA were the most active atany concentrations, and the optimum concentration was 20 mM. The L-formdid not show a significant difference in activity at any concentrations,as compared with the control group (containing no HBA). The D,L-form didnot show a significant difference at concentrations of 5 mM and 20 mM,as compared with the control group.

Example 4

Using four types of the testing irrigating solutions described inExample 1, i.e., Solutions No.1 and No.2 and Comparative Solutions 1 and2, their cornea-protecting effects were compared with one another byperforming an in vitro experiment.

Sclerocorneas (5 pieces for each of the four testing solutions, 20pieces in total) having about-5-mm-wide sclerae around the corneas wereextracted from mature rabbits and incubated in the testing irrigatingsolutions at 36° C. for 5 hours. The corneal thicknesses were measuredby an ultrasonic pachymeter (DGH-500 PACHETTE, a product of DGHTECHNOLOGY).

The amounts of changes in the corneal thickness (=the corneal thicknessbefore incubation—the corneal thickness after 5-hr incubation) after the5-hr incubation of each testing solution are shown in FIG. 2.

Solution No.1 containing D-3-HBA and bicarbonate ions showed aremarkable cornea-protecting effect, as compared with Solution No.2containing no bicarbonate ions. Further, Solution No.1 also showed acornea-swelling-inhibiting effect which is the same as or greater thanthose of commercially available Comparative Solutions 1 and 2.

Example 5

Four types of the testing irrigating solutions described in Example 1,i.e., Solutions No.1 and No.2 and Comparative Solutions 1 and 2, werealso investigated for their effects to the corneal thickness by an invivo experiment in which the solutions were irrigated in the anteriorchambers of Dutch rabbits (male and female weighing 1.9 to 2.9 kg).

Experiments were performed in rabbit, anesthetized with intramuscularxylazine hydrochloride (“celactal®”, a product Bayer AG.,) and ketaminehydrochloride (“ketalar®”, a product of Sankyo Co. Ltd,.). A 3.2-mm-wideincision was made around the corneas of the left and right eyes of eachrabbit using a scalpel for ocular surgery. Subsequently, 18-gaugeinjection needles having a rounded tip were inserted in the anteriorchambers through the incisions, and the four types of testing irrigatingsolutions were allowed to irrigate at a flow rate of 10 ml/min for 120minutes. The amount of change in the corneal thickness by each solutionwas measured by the above ultrasonic pachymeter before the start of theirrigation and every 30 minutes after the start of the irrigation underlocal anesthesia maintained by giving eye drops of a 0.4% oxyprocainehydrochloride solution. The amounts of changes in the cornealthicknesses with time are shown in FIG. 3.

As a result, FIG. 3 shows that Solution No.1 containing D-3-HBA andbicarbonate ions is a preparation of irrigating solution which causes asignificantly small change in the corneal thickness and which has anexcellent cornea-protecting effect as compared with Solution No.2containing no bicarbonate ions and with Comparative Solutions 1 and 2,as in the result of the in vitro experiment of Example 4.

Example 6

As an invasive model assuming a phacoemulsification and aspirationmethod used as a surgical method of cataract, incubated bovine cornealendothelial cells damaged by ultrasound were subjected to an experimentfor examining the recovery of their barrier function.

Using the incubated bovine corneal endothelial cells damaged byultrasound, the barrier function-recovering effects of D-3-HBA andoxyglutathione were subjected to an experiment in accordance with thefollowing procedure.

The monolayer of cultured bovine corneal endothelial cells on a filter,which had been damaged by sonication to the cells at 92 W/cm² threecourse at intervals of 0.1 sec, was incubated in DULBECCO's MEM medium(with 10% of embryonic bovine serum) containing 20 mM of D-3-HBA or 0.3mM of oxyglutathione. FIG. 4 shows the results of measuring the degreesof recovery of the barrier function by using a change in the electricalresistance value of the endothelial layer with time as an index.

The monolayer in the medium containing D-3-HBA showed an electricalresistance value closer to the value before the irradiation ofultrasound at any observation time than those in the MEM mediumcontaining oxyglutathione and the MEM medium containing neither D-3-HBAnor oxyglutathione, and it showed a quick recovery effect of the barrierfunction.

Example 7

Irrigating solution No.1 (Example) and solutions No.3, No.4 and No.5(Comparative Examples) for testing were prepared by dissolving thepredetermined amounts of the components listed in Table 2 and, finally,D-3-HBA so as to adjust the total amounts of the aqueous solutions to be1 liter; adjusting the pHs of the solutions by diluted hydrochloricacid, and subjecting the solutions to aseptic treatment.

TABLE 2 (mM) containing containing no Solution bicarbonate saltsbicarbonate salts No. 1 3 4 5 D-3-HBA 20 0 0 20 NaCl 100.3 122.0 145.4123.7 KCl 5.1 5.1 5.1 5.1 Na₂HPO₄ 3.0 3.0 3.0 3.0 sodium citrate 0.340.34 0.34 0.34 MgCl₂ 1.0 1.0 1.0 1.0 CaCl₂ 1.1 1.1 1.1 1.1 NaHCO₃ 25.025.0 — — glucose 5.0 5.0 5.0 5.0

Dutch rabbits (male and female weighing 1.9 to 2.9 kg) were used for anexperiment. Experiments were performed in rabbit, anesthetized withintramuscular xylazine hydrochloride (“celactal®”, a product Bayer AG.,)and ketamine hydrochloride (“ketalar®”, a product of Sankyo Co. Ltd,.)through intramuscular injection, a 3.2-mm-wide incision was made corneaslimbusing a scalpel for ocular surgery. Subsequently, 18-gauge injectionneedles having a rounded tip were inserted in the anterior chambersthrough the incisions, and the irrigating solutions were allowed toirrigate at a flow rate of 10 ml/min for 90 minutes. After theirrigation, the incisions were sewed up once by a sewing needle with asuture. The corneal thicknesses were measured by the ultrasonicpachymeter used in Example 4 before and during the perfusion (atintervals of 30 minutes).

The effect of D-3-HBA to keep a change in the corneal thickness small byadding D-3-HBA and bicarbonate ions to the intraocular irrigatingsolutions was significant (FIG. 5). On the other hand, in the case ofthe preparations in which the bicarbonate ions were not added to theintraocular irrigating solutions, the effect of keeping the change inthe corneal thickness small by D-3-HBA was not significant (FIG. 6).

As described above, according to the present invention, by using sodiumD-3-hydroxybutyric acid and/or salts thereof, bicarbonate ions,phosphate ions, calcium ions, magnesium ions and, in some cases, citrateions in combination as an energy source, a preparation of irrigatingsolution for ocular surgery could be prepared that is highly safe as anirrigating solution for ocular surgery, has an excellent effect ofprotecting ocular tissues including corneal endothelial cells and anexcellent effect of recovering physically damaged ocular tissues, and isstabilized by adding inorganic salts, isotonic agents, glucose, buffersand stabilizers.

What is claimed is:
 1. A one solution-pack preparation of irrigatingsolution for ocular surgery of cataract, glaucoma or intraocular lenstransplantation, which comprises an aqueous solution containing: (1) atleast 0.1 mM but less than 500 mM of at least one compound selected fromthe group consisting of D-3-hydroxybutyric acid and water-soluble saltsthereof as a D-3-hydroxybutyrate anion; (2) at least 0.1 mM but lessthan 100 mM of water-soluble bicarbonate salts as a bicarbonate ion; (3)at least 0.1 mM but less than 50 mM of at least one compound selectedfrom the group consisting of phosphoric acid and water-soluble phosphatesalts thereof as a phosphate ion; (4) at least 0.01 mM but less than 50mM of water-soluble calcium salts as a calcium ion; and (5) at least0.01 mM but less than 50 mM of water-soluble magnesium salts as amagnesium ion.
 2. The preparation of claim 1, wherein the water-solublesalts of D-3-hydroxybutyric acid are selected from the group consistingof the sodium salts, potassium salts, barium salts, magnesium salts,lithium salts, L-lysine salts, L-histidine salts and L-arginine salts ofD-3-hydroxybutyric acid.
 3. The preparation of claim 1, wherein thewater-soluble bicarbonate salts are sodium bicarbonate or potassiumbicarbonate.
 4. The preparation of claim 1, wherein the water-solublephosphate salts are selected from the group consisting of sodiumdihydrogen phosphate, disodium hydrogen phosphate, potassium dihydrogenphosphate and dipotassium hydrogen phosphate.
 5. The preparation ofclaim 1, wherein the water-soluble calcium salts are selected from thegroup consisting of calcium chloride, calcium glycerophosphate andcalcium glucuronate.
 6. The preparation of claim 1, wherein thewater-soluble magnesium salts are magnesium chloride or magnesiumsulfate.
 7. The preparation of claim 1, further containing water-solublecitric acid and/or salts thereof.
 8. The preparation of claim 7, whereinthe water-soluble citrate salts are sodium citrate or potassium citrate.